Storage bins of the type which are stackable to form a storage bin system are known in the art. For example, in one type of system one bin above merely rests on a bin below without any positive interconnection between the bins of the stack. As such, not only is there a stability problem, but also if the user wishes to carry the stack of bins, he must inconveniently do so by grasping the bottom bin because if he engages the top bin, it will merely be removed from the stack.
In an attempt to eliminate these problems, one known stacking bin system includes bins having a rib on the bottom with apertures therein and a rim on the top with similar apertures therein. By aligning the bottom apertures of one bin with the top apertures of another bin, and by installing pop rivets through the aligned apertures, the two bins may be interconnected. The deficiencies of this system are that the extra small pop rivets are required which are not only quite susceptible to being lost, but also they could tend to wear and become ineffective after multiple uses.
Some of the aforementioned storage bin systems have been rendered mobile by the application of wheels to the bottom bin of the stack. In instances where the wheels might be permanently attached to the bin, this of course requires that the particular bin with the wheels is the only one usable as the bottom bin of a system. In some systems the bins are provided with additional feet which may receive casters therein, but such additional feet add to the expense of the product and in addition often prohibit the economically advantageous nesting of the bins as is desirable for shipping, retail display, and consumer storage.
Thus, the need exists for a storage bin system which is readily and securely stackable, as well as optionally nestable, and for one which can be conveniently rendered mobile to form a cart system.